1. Field of the Invention
The present invention relates to a medical image processing apparatus and a medical image processing method.
2. Description of the Related Art
In diagnoses of stroke, a brain perfusion technology is useful. According to this technology, a brain perfusion image as an image showing a recirculation state of blood is created from a tomographic view of a brain taken after injection of a contrast media, and this image is often used for diagnoses for stroke.
In recent years, to three-dimensionally grasp a positional relationship between a blood vessel and a lesion, digital subtraction angiography (DSA) is used. In this DSA, 3D-DSA adopting a three-dimensional photographing method based on photography in many directions rather than photography in one direction or rotational DSA photography is often utilized.
As a technology concerning the 3D-DSA, for example, JP-A 2005-80285 (KOKAI) discloses the following technology. That is, in JP-A 2005-80285 (KOKAI), a necessary part in a subject is photographed without including an image of a contrast media, and image data of a mask image as an X-ray image is collected. Then, the necessary part including an image of the contrast media is photographed, and image data of a contrast image as an X-ray image is collected. Further, the mask image and the contrast image having the same projection angle are subjected to subtraction. Contrast blood vessel figure three-dimensional image data is reconfigured from this subtraction image. Furthermore, the mask image and air-calibration image data are subjected to subtraction, and human anatomy figure three-dimensional image data is reconfigured from this subtraction image. Moreover, the contrast blood vessel figure three-dimensional image data is combined with the human anatomy figure three-dimensional image data to be displayed. Based on this display, it is possible to clearly grasp not only detailed information of the blood vessel but also a relationship between the blood vessel and the human anatomy, especially between the blood vessel and bones.
With advancement of interventional radiology (IVR) technology in recent years, an X-ray intervention is often used for treatments of blood vessel disorders. In the X-ray intervention, a material such as plaque may scatter peripherad due to a treatment for widening stenosis by using a balloon and hence a peripheral blood vessel may possibly clogs. In such a case, thrombolysis must be rapidly performed. At this time, a time until a blood clot dissolves and a blood stream in a corresponding peripheral blood vessel is restored is an index representing a degree of dysfunction that remains in the brain.
At the present day, there is no clinically established brain perfursion technology that can be used in the X-ray intervention. Therefore, at the end of the X-ray intervention, whether an artery having a given thickness is clogged is just confirmed.
It is to be noted that CT examination conducted after the end of the X-ray intervention may enable discovering an abnormality, e.g., clog in a very thin artery or a capillary blood vessel by a blood clot in some cases. However, it is often the case that the CT examination is generally carried out at least 2 or 3 hours after the end of the X-ray intervention or on the following day of the X-ray intervention. Therefore, even if a thrombolytic therapy is rapidly effected after this discovery, a certain level of disorder may remain in the brain function in some cases.